dog1 = {'color':"white",'age':12}
print(dog1['color'])
print(dog1['age'])
dog1['name'] = 'Xiao'
print(dog1)
del  dog1['name']
print(dog1
      )
for key,value in dog1.items():
    print(key)
    print(value)
print(type(dog1.keys()))